On 3/22/06, Robert McGwier <[EMAIL PROTECTED]> wrote: > Let me say that I am now of the opinion that all of this high resolution > clock business was something of a diversion from the real problems. >
That was my opinion all along, but I didn't want to touch the subject, since I have never used the keyer myself. The high-resolution performance counter frequency doesn't necessarily relate to the ACPI version. For example, Tim's system probably has the "dual core performance fix" applied (with /usepmtimer in boot.ini), so he will get the ~3.5 MHz reading even if his system is ACPI 2.0. PMTimer is the ACPI power management timer. Regardless of ACPI version, it always runs at 3,579,545 Hz (which is closely related to the original 4.77 MHz PC clock frequency). If your perf counter freq == 3,200,000,000, then the system is obviously not using ACPI PMTimer. Instead it's reading the CPU's time stamp counter: http://faydoc.tripod.com/cpu/rdtsc.htm You don't even need inline assembler for this operation, because recent Microsoft compilers have it as an intrinsic function __rdtsc(). Getting back to the more important point: > It is time to revisit the question: are there folks getting reasonable > CW performance using the "high res" timer in the code even though > perf.exe reports 3.5 MHz? Unfortunately I can't test this myself, but 3.5 MHz really should be fast enough for CW. If there still are some problems, you need to look elsewhere for the reason. 73, Sami OH2BFO
